High performance of metal-on-metal bearings: a case report.

There has been considerable initial success with the use of total hip and resurfacing metal-metal implants tempered by poor performance of certain bearing designs, specifically small and/or abnormal component orientation. With a growing number of reports relating to adverse local tissue reactions, the need to monitor ion levels is crucial. This report presents a case of an extremely active bilateral metal-metal implant patient who had severe arthritis of the left hip and was originally treated with a cementless metal-on-polyethylene surface replacement. This implant lasted 12~years and after complete wear through of the polyethylene, the prosthesis was converted to metal-on-metal total hip. The patient continued to cycle vigorously and engaged in downhill skiing. Eventually his contralateral hip developed arthritis and he underwent metal-on-metal surface arthroplasty. Since his last surgery 8~years ago, the patient has resumed his activities, cycling an average of 6,400 miles and skiing over 60~days a year. He has been followed clinically and radiographically for 23 years with ion levels measured serially.